The SARS-CoV-2 and influenza viral load in wastewater is being tested at selected wastewater treatment plants (WWTP) in Germany as part of AMELAG (“Abwassermonitoring für die epidemiologische Lagebewertung”, German for wastewater monitoring for epidemiological situation assessment). In 2025, up to 70 wastewater treatment plants are to be sampled for SARS-CoV-2. The data collected will be integrated into this report in the coming weeks. For the calendar week 6 data from 61 WWTPs were available. Data from other WWTPs are provided continuously.
An assessment of the overall situation is conducted in conjunction with other indicators in the weekly report on acute respiratory diseases (ARE weekly report). A comparison between the aggregated SARS-CoV-2 viral load in wastewater and the COVID-19 incidence is shown in the weekly Grippeweb report.
The course of the viral loads aggregated across all sites is shown in Figure 1 in order to obtain an overall picture of the mean viral load and its development in Germany. Weekly mean values of the viral loads (given in gene copies / liter), previously transformed by the common logarithm, are computed, first for each site and then across all sites for the respective week. The mean values are weighted according to the number of inhabitants connected to the respective site. The estimation of the regression curve is also weighted, so that weekly mean values with higher uncertainty are given a lower weight in the estimation and vice versa. Recently, a slightly decreasing aggregated SARS-CoV-2 viral load can be observed. The development observed over the last few weeks may still change due to late notifications, especially from WWTPs with large population coverage.
Figure 1: Aggregated SARS-CoV-2 load in wastewater over time
(grey dots) along with a regression curve (black line, estimated using
the LOESS method) and associated 95% confidence intervals (light blue
area). The change from the first to the second AMELAG phase, which was
associated with a sharp decline in the number of participating treatment
plants, is indicated by a vertical dashed line. The data was last
updated on Tuesday the 11.02.2025, 10 am. The latest data used in the
calculations is from the previous Wednesday’s sampling (05.02.2025, CW
6). Shown are 7-day averages, which refer to the period from Thursday to
Wednesday; the most recent value is calculated from the data from
30.01.2025 (CW 5), to 05.02.2025 (CW 6). The date of the sample
corresponds to the start date of the 24-hour composite sample.
The button
on the right allows the display of the data points, regression curve and
confidence intervals on the logarithmic scale or transformed back to the
original scale. Changes in viral loads in the low value range are
emphasized more strongly than values in the high value range on a
logarithmic scale. By hovering over the individual points the calendar
week, the date of the corresponding Wednesday, the viral load, the
number of sites and the proportion of the total population that is
included in the calculation at that time are shown.
Data for
further sites are supplied subsequently.
The course of the viral load in wastewater is shown for the individual WWTPs in Figure 2.